Mg-Pb phase diagram and phase transformations in the intermetallic compounds Mg2Pb and β

Welding is a non-equilibrium process. However, some weldability issues, as the extension of the heat-affected zone (HAZ) can be addressed using equilibrium phase diagrams. The 70 wt% Fe-Cr-Ni pseudo-binary phase diagram is commonly used to establish the phase transformations during welding of duplex stainless steels. The predicted results are assumed to be reasonably good for most of the duplex stainless steels. Thermodynamic calculations were used to determine multicomponent phase diagrams and volumetric fraction of phases present as a function of temperature several commercial duplex stainless steels. Results showed that simplified pseudobinary phase diagram approach is valid to estimate welded joint microstructures only for the low alloy duplex stainless steels as UNS S32304, but phase transformations and mainly solidification paths of high alloy duplex stainless steels should predicted only using a multi-component phase diagram.

Download Full-text

Thermodynamical Estimations on the Amount of Liquid Phase During Reaction Synthesis of Nickel-Aluminides

MRS Proceedings ◽

10.1557/proc-364-561 ◽

1994 ◽

Vol 364 ◽

Cited By ~ 2

Author(s):

Seiji Miura ◽

Yoshinao Mishima

Keyword(s):

Phase Diagram ◽

Liquid Phase ◽

Intermetallic Compounds ◽

Binary Phase Diagram ◽

Shape Change ◽

Heat Of Formation ◽

Nickel Aluminides ◽

Reaction Synthesis ◽

Estimation And Control ◽

And Control

AbstractThe amounts of intermetallic compounds and liquid phase are estimated as a function of temperature during reaction syntheses for Ni–Al binary alloys having arbitrary compositions under adiabatic conditions. It is assumed that the phases that would present during the process are only those appearing in the equilibrium binary phase diagram. Calculations are done by using available data on heat of formation of intermetallic compounds and those on enthalpy of liquid phase. The results obtained arc discussed in view of the estimation and control of the amount of liquid phase, which is significant for the densification and shape change of materials.

Download Full-text

Thermodynamic Calculation of Bi-Au-Lu, Nd Ternary Systems

Materials Science Forum ◽

10.4028/www.scientific.net/msf.850.444 ◽

2016 ◽

Vol 850 ◽

pp. 444-451

Author(s):

Shu Liang Wang ◽

Lu Jiang Zhou ◽

Jia Lian Li ◽

Xiao Hong Wang ◽

Yuan Hua Lin ◽

...

Keyword(s):

Phase Diagram ◽

Intermetallic Compounds ◽

Binary Systems ◽

Ternary Systems ◽

Free Energies ◽

Gibbs Energies ◽

Solution Models ◽

New Type ◽

Free Solder ◽

Kister Equation

With available melting point and hardness, the Bi-based filler alloy is considered as one choice of high-temperature Pb-free solder. Phase diagram can play an important role in the design of new type of Pb-free solder.In the present work, the thermodynamic assessments of the Au-Nd and the Au-Lu binary systems have been carried out by the Calculation of Phase Diagram (CALPHAD) method based on the available experimental data. The Gibbs free energies of the solution phases were described by subregular solution models with the Redlich-Kister equation, and those of the intermetallic compounds were described by sublattice models. A set of self-consistent and reasonable thermodynamic parameters is obtained for the binary systems, which describes the Gibbs energies of the solution phases and the intermetallic compounds phases. Additionally, combined the reported Bi-Au, Bi-Lu and Bi-Nd binary systems, the thermodynamic database of the Bi-Au-Lu and the Bi-Au-Nd ternary systems have been developed, which will provide important thermodynamic information for the phase equilibria of the multicomponent Bi-based alloy systems.

Download Full-text